We present a chemical vapor deposition(CVD)method for the growth of uniform single-walled carbon nanotube(SWNT)arrays on a stable temperature(ST)-cut single crystal quartz substrate using a mixture of methanol and ethanol as carbon source.It is found that introducing methanol during the growth can improve the density and the length of the well-aligned SWNTs in the arrays as well as increase the SWNT/quartz interaction.Obvious“up-shifts”of G-band frequencies in the Raman spectra have been found for the aligned SWNTs.A well-designed control experiment shows that the G-band“up-shifts”originate from the strong interaction between SWNTs and the quartz substrate.It is believed that exploring this interaction will help to elucidate the growth mechanism;ultimately,this will help realize the promise of controlling the chirality of SWNTs.
Lei DingWeiwei ZhouThomas P.McNicholasJinyong WangHaibin ChuYan LiJie Liu
1-dimensional (1D) metal-semiconductor nano-scale composite superstructures based on Au nanoparticles and CdS nanorods were prepared.The outer surface of CdS nanorods was modified with mercapto-ethylamine (MEA) in advance.With the aid of MEA,dense and uniform Au nanoparticles were deposited onto the external wall of CdS nanorods through in situ chemical reduction of AuCl4-ions.Those Au nanoparticles induced further electroless deposition and a continuous layer of Au was formed on CdS nanorods.Stable hollow Au tubes were obtained after the inner CdS cores were etched by HCl.UV-Vis,FL,XPS,EDX,TEM and SEM measurements were carried out to characterize the produced materials.The quenching of the defect emission of CdS in CdS-nanorod/Au-nanoparticle hybrid superstructures was detected,which was ascribed to the energy transfer from the exciton of CdS to surface plasma resonance level of Au.
YANG ZhaoHui CHU HaiBin JIN Zhong ZHOU WeiWei LI Yan
